The Claim

In overweight postmenopausal women undergoing weight loss, the rate of weight loss and the magnitude of energy deficit are stronger predictors of fat-free mass loss than protein intake, accounting for up to 39% of the variance in lean tissue reduction.

Source: Impact of Protein Intake during Weight Loss on Preservation of Fat-Free Mass, Resting Energy Expenditure, and Physical Function in Overweight Postmenopausal Women: A Randomized Controlled Trial

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
70score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Correlation
1 study reviewed
In plain English

In overweight postmenopausal women losing weight, how quickly they lose weight and how large their calorie deficit is predict more of the loss of lean tissue than how much protein they consume, together explaining up to 39% of the variation in lean mass loss.

See the scientific wording

The rate of weight loss and the magnitude of energy deficit are stronger predictors of fat-free mass loss than protein intake in overweight postmenopausal women, explaining up to 39% of the variance in lean tissue reduction during weight loss.

Why this might work

When the body loses weight too quickly and burns far more calories than it takes in, it breaks down muscle tissue to get energy because it cannot rely on fat alone. This happens even if the person eats a lot of protein, because the body prioritizes immediate energy needs over preserving muscle.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Impact of Protein Intake during Weight Loss on Preservation of Fat-Free Mass, Resting Energy Expenditure, and Physical Function in Overweight Postmenopausal Women: A Randomized Controlled Trial

    This study found that how fast you lose weight and how few calories you eat matter more for losing muscle than how much protein you eat — and together, they explained almost 40% of why some people lose more muscle than others.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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